Tamper-proof bottle cap and container

ABSTRACT

An improved bottle cap and container are disclosed. The cap is composed of a top disk, a thin-walled outer skirt and a thinwalled inner skirt both attached to the disk. The outer skirt is weakened along two circumferential score lines to form a weakened cylindrical band around the outer skirt. A tab is attached to the cylindrical band and extends outwardly to provide a means whereby a person may grasp the tab between the fingers and tear the band from the cap. The outer skirt also has two circumferential beads attached to the inside of the skirt with one bead being disposed above the band and one below the band. These beads fit in grooves in the container neck. Prior to tearing the band from the skirt, the cap is tamper-proof. When the band is removed the portion above the band functions as a reclosure cap.

United States Patent 11 1 Cochrane TAMPER-PROOF BOTTLE CAP AND CONTAINER[76] Inventor: Ben A. Cochrane, 210 E. Linda Mesa Ave, Danville, Calif.94526 221 Filed: Feb. 13, 1975 1211 Appl.No.:549,512

Primary Examiner-George T. Hall Attorney, Agent, or Firm-Michael D.Nelson 1 Dec. 23. 1975 ABSTRACT An improved bottle cap and container aredisclosed. The cap is composed of a top disk, :1 thin-walled outer skirtand a thin-walled inner skirt both attached to the disk. The outer skirtis weakened along two circumferential score lines to form a weakenedcylindrical band around the outer skirt. A tab is attached to thecylindrical band and extends outwardly to provide a means whereby aperson may grasp the tab between the fingers and tear the band from thecap. The outer skirt also has two circumferential beads attached to theinside of the skirt with one bead being disposed above the band and onebelow the hand. These beads fit in grooves in the container neck. Priorto tearing the band from the skirt, the cap is tamper-proof. When theband is removed the portion above the band functions as a reclosure cap.

7 Claims, 9 Drawing Figures US. Patent Dec. 23, 1975 F/Gz 3 Sheet 1 of 2US. Patent Dec. 23, 1975 Sheet2of2 3,927,784

TAMPER-PROOF BOTTLE CAP AND CONTAINER This invention relates to a newimproved bottle cap. More particularly, this invention relates to animproved recloseable plastic bottle cap.

BACKGROUND OF THE INVENTION Plastic caps for narrow necked plasticbottles are typically of the type disclosed in US. Pat. No. 3,338,446.The caps have a depending thin-walled skirt weakened approximatelymidway of its length with a circumferential score line so that theportion of the skirt below the score line may be torn off. The cap hastwo beads which extend circumferentially around the inside of the cap.These beads fit into grooves in the bottle neck and prevent the cap frombeing removed from the container. When both beads are in place the capcannot be removed thereby preventing any tampering with the bottlecontents. The lower bead is torn away when the lower skirt is removed.This then allows the cap to be easily pried over the upper bead to allowaccess to the contents. The upper bead remains with the cap therebyallowing the cap to be used repeatedly for reclosure until the contentsof the bottle are exhausted.

There are several problems with the plastic caps of the prior art. Amajor problem is the splitting of the lower portion of the cap when itis forced onto bottle neck. The score line for the tear-away lowersection extends diagonally through the lower portion of the cap skirtand terminates at its rim. This score line weakens the cap rim and whenpressure is exerted in an attempt to push the cap onto the bottle, thecap rim often tears along this score line. Bottles with torn rims mustbe removed from the packaging line, the cap manually removed and thebottle and contents recycled. This tearing problem, referred to as a capsplitting, is a substantial burden and significantly increases operatingexpenses.

Another problem with the prior art caps is the difficulty by theconsumer in tearing the lower skirt from the cap. The problem is caused,in part, by the manufacturer when it strengthens the score line for thepurpose of reducing cap splitting" as discussed supra. By strengtheningthe score line, the amount of force or difficulty" required to tear thelower skirt from the cap is proportionately increased.

In addition, the score line as it extends diagonally through the lowerskirt of the cap, must penetrate the lower bead which extendscircumferentially around the inside of the cap. Because the beadincreases the thickness of the skirt at this point, the score line doesnot cut into the skirt as deeply thereby increasing the difficulty intearing the lower skirt from the cap.

Another problem existant with the prior art caps is the loose fit of thecap onto the bottle. A tight fit between the cap and the bottle isessential for a good seal. Although the prior art caps could be made tofit more tightly on the bottle, such an improvement would result in agreater number of cap splitting. Thus an improvement in fit or seal isoff-set by an increase in split caps and operating costs.

A need thus exists for a tamper-proof cap which can be used repeatedlyfor reclosure, which can be inserted onto the bottles without capsplitting, which can be removed from the bottle by the consumer withoutgreat difficulty, which has a tight fit or good seal and which 2 isrelatively easy to produce and inexpensive to manu facture.

It is therefore an object of this invention to provide an improvedplastic cap.

It is an additional object of this invention to provide an improvedplastic cap which does not split when inserted onto a container.

It is a further object of this invention to provide an improved plasticcap which may be removed from the container without difficulty.

Another object of this invention is to provide an improved plastic capwhich fits tightly on the container neck and provides improved sealingof the container contents.

It is a further and additional object of this invention to provide acontainer and improved cap combination.

SUMMARY OF THE INVENTION The aforementioned objects and their attendantadvantages can be realized by a deformable plastic cap comprising l) atop disk, (2) a cylindrical thin-walled outer skirt integrally attachedto and extending substantially perpendicularly from said disk and (3) acylindrical inner skirt integrally attached to and substantiallyperpendicular to the disk positioned inward and enclosed within saidouter skirt and substantially coaxial therewith and extending for ashorter distance than the outer skirt. The outer skirt is scored andweakened along a circumferential first score line downwardly spaced fromthe disk. The outer disk is also scored and weakened along acircumferential second score line downwardly spaced from the first scoreline to form a weakened cylindrical band within the outer skirt. A teartab is attached to the cylindrical band and extends outwardly from theouter skirt and downwardly from the cylindrical band. An area connectingthe first and second score lines, adjacent the tear tab, is weakened toallow easy tearing of the cylindrical band from the cap. In order tohold the cap to the container neck, two narrow radial beads are providedwhich extend circumferentially around the inside and integrally attachedto the outer skirt. One head is positioned above the cylindrical bandand one bead is positioned below the band.

This cap is not burdened with the splitting problem of its prior artcaps since there is no score line extending to the bottom of the cap.The cap of this invention can be manufactured with a strong lower skirtwithout increasing the difficulty of removing the tear band by theconsumer. Also, the cap can be inserted onto a container with a tighterfit thereby realizing an improved seal for the container contents.Moreover, since the score line in the cap of this invention does notbisect the lower bead, this cap is not burdened by the difficulty intearing the lower skirt from the cap as experi' enced with many of theprior art caps.

Other related and additional objects of this invention will be apparentfrom the drawing, the following description of the invention andappended claims.

In the drawings:

FIG. I is a top view of a cap in accordance with thl invention.

FIG. 2 is a sectional view of a cap taken substantially along line 2-2of FIG. 1.

FIG. 3 is a side view of the cap showing the kirt.

FIG. 4 is a fra mentary side view of a sap shewin the connection of atear tab to the skirt.

FIG. 5 is a perspective view 6f the cap.

FIG. 6 is a perspective view of the top portion of the cap with the tearband and lower skirt removed.

FIG. 7 is a perspective view of the tear band after its removal from thecap.

FIG. 8 is a perspective view of the lower skirt after its removal fromits cap.

FIG. 9 is a cross-sectional view of the cap on a container neck.

DETAILED DESCRIPTION OF THE INVENTION When references are made to theaccompanying drawings the similar characters of reference representcorresponding parts in each of the several views.

Cap 1 is constructed in accordance with the present invention from aresilient and moderately flexible plas tic substance so that it willdeform slightly to snap on and off of the container. Exemplary plasticmaterials which may be employed include polyethylene, polystyrene,polyvinyl, chloride, polyacrylates, polyamides, polypropylene, etc. Thepreferred plastics are polyethylene and polystyrene.

Cap 1 is comprised of three different sections, a top disk 2, an outerskirt 4 and an inner skirt 6. The top disk 2 is preferably a flatcircular plate having a substantially planer exterior surface. This flatexterior surface provides a convenient place for labels or instructionalmaterial. It should be recognized that the disk can have a shape otherthan circular. For example the disk can be rectangular, oval, or other.In a preferred embodiment the disk is circular and extends beyond thecylindrical outer skirt to form a circumferential lip 10 around the cap.This lip thereby provides a convenient means for facilitating theremoval of the upper portion of the cap from the container. Thus, theconsumer, after removing the tear band from the cap, can open thecontainer by applying pressure upwardly on the lip 10 by the thumb orfinger. This action will unseat the upper bead from the upper groove andallow the cap to slide off the container neck.

The outer skirt 4 of Cap 1 is integrally attached to the top disk 2 andextends substantially perpendicularly from the planner surface of thedisk. The outer skirt 4 is a thin-walled cylindrical shell and iscomposed of the thin shell, an upper score line 14, a lower score line16, tear tab 24, an upper circumferential bead l8 and a lowercircumferential bead 20. The thickness of the skin is not critical tothe practice of this invention as long as the cap is sufficientlyresilient to allow the internal beads 18 and to expand over the wideareas of the container neck and snap into the container grooves withouttearing of the cap or container. Generally, however, the skirt thicknessis governed by economies with the thinnest functional cap beingpreferred. Usually the thin shell will have a thickness ranging from 0.3millimeters (mm) to [.5 millimeters and more usually from 0.5 mm to lmm.

The upper score line 14 extends circumferentially around the skirt 4forming a circular weakened line entirely enclosing the skirt. The scoreline 14 may be made on either the inner or. outer surface of the skirt.

The lower score line 16 is the same as the upper score line except thatit is disposed at a lower position around the skirt. Like the upperscore line, the lower score line may be made on either the inner orouter surface of the skirt. The portion of the outer skirt between scoreline 14 and score line 16 is the tear band 22. This band is removed whenthe consumer wishes to open the container and after it is removed fromthe cap it is dis- 4 carded. Because it is discarded, it is preferred tomake the band as narrow as possible without weakening the band to thepoint where it could break during removal. Generally, the tear band willrange in width from 2 mm to 10 mm.

A tear tab 24 is attached to the tear band 22 and provides a means forthe tear band to be torn from the cap by the consumer. The tear tab 24may be any projecting tab which allows the consumer to easily grasp thetab by the fingers. In a preferred embodiment, the tab 24 extendsoutwardly from the tear band 22 and then downwardly terminating aposition below the rim 26 of its outer skirt. By extending the tab belowthe rim of the skirt, the tab may be used as a guide in automaticcapping machines to guide the cap within the machine and onto thecontainer. In order to increase the friction between the fingers andtear tab, the tab is preferably grooved with serrates 28 or the like.

A weakened area extends from the lower score line 16 to the upper scoreline 14 substantially adjacent to tear tab 24. The weakened area isprovided so that the tear band may be a gap in the band such as shown inthe drawings or may be a score line extending vertically between the twocircumferential score lines 16 and 14.

Upper and lower internal circumferential beads are provided around theinterior of the outer skirt which fit into grooves in the container andhold the cap firmly onto the container neck. The upper bead l8isdisposed above the first score line between the score line 14 and thetop disk 2. The lower bead 20 is disposed below the second score linebetween the score line, 16 and the rim 26. The beads 18 and 20 aresubstantially uniform raised surfaces projecting inwardly from theskirt. In one embodiment, the raised surface has a semi-circularcross'section; in another it may be triangular. In another embodiment,the raised surface may extend substantially horizonally at its upperarea and curve downwardly and outwardly to the skirt at its lower area.The type, shape and size of the beads can be the same as the beadsdiscussed in US. Pat. Nos. 3,338,446 and 3,672,528, which patents areherein incorporated by reference.

The inner skirt 6 of cap 1 is integrally attached to the top disk 2inward from the outer disk and extends substantially perpendicular tothe planner surface of the disk. The inner skirt 6 is disposed inwardand enclosed within the chamber of the outer skirt and substantiallyco-axial therewith. The inner skirt 6 extends for a dis tance shorterthan the outer skirt and preferably terminates before the first scoreline 14. More preferably the inner skirt 6 terminates adjacent to orbefore the upper bead 18. The inner skirt 6 and the outer skirt 4 forman annular chamber in which the container neck is held. The inner skirtis disposed so that it tightly fits into the opening of the containerneck, and the outer skirt is disposed so that it tightly fits along theoutside of the container neck. The annular chamber 34 is preferablyshaped at its top with rounded interior surface 28 to provide a sealwith the rounded exterior surface 30 of the container neck lip. Theterminus of the inner skirt 6 is preferably slanted inward such as byinwardly curving exterior surface 32. Tenninating the inner skirt inthis manner allows the inner skirt to guide the top of the containerneck into the annular chamber 34.

The caps are conveniently prepared by an injection mold technique.Although the injection mold is by far the most convenient, it isrecognized that other methods for making the cap can be used.

The cap I is primarily for use with a thin-walled plastic container 36.The container is usually fairly strong and lightweight. Although thewalls are reasonably rigid, there is generally sufficient resiliency inthe plastic materials so that they will flex slightly under pressure.

The shape of the lower portion of the container 36 is subject toconsiderable variation as is well understood in the plastic bottle art.Neck 38 projects upwardly from the main portion of the container. Neck38 is an elongated upwardly-inwardly shaped cylindrical thinwalledshell. At the upper end of neck 38 are two pcripherally disposedcircumferential grooves 40 and 42. A cylindrical shell 44 extends upfrom the upper groove 40 and terminates, in a perferred embodiment, in asmooth rounded container lip 30, The upper groove 40 is disposed so thatit encounters bead 18 of cap I when the cap is inserted onto thecontainer. The lower groove 42 is disposed so that it encounters bead ofcap 1 when the cap is inserted onto the container. The circumferentialgrooves may be of triangular, circular, rectangular or othercross-section and are preferably of the same cross-section as the capbeads. The type, size and shape of the container can be as shown anddescribed in U.S. Pat. No. 3,338,446.

In using the cap and the combination of this invention, after thecontainer 36 has been filled with a product, the cap 1 is installed.Automatic machinery may be used for this purpose. Outer skirt 4 isslipped on outside neck 38 and a downward pressure is applied. The toprim of the container neck encounters slanted surface 32 which guides thelip between skirts 4 and 6. As the downward pressure is continued, thebeads 18 and 20 slide over the surface of neck 38 and snap into grooves40 and 42. The flexible nature of the plastic material of which the capis fabricated, permits this temporary deformation of the parts. Thusassembled, the container is sealed since the cylindrical shell 44 isheld tightly between skirts 4 and 6 and the rounded lip 30 is contactedby the rounded interior surface 28 of the cap. It is nearly impossibleto remove the cap 1 while skirt 4 is intact.

When the consumer wishes to open the container, he grips the tear tab 24and pulls outwardly tearing tear band 22 from the outer skirt 4. Thelower portion of the outer skirt remains on the container completelysevered from cap 1. The portion of the cap above the tear band comprisesa re-closure cap for the container 36. Such re-closure cap may be priedoff by lifting on lip 10. This operation is possible where there is onlya single bead 18 in position in groove 40. When skirt 4 is intact beforethe tear band is removed, it is almost impossible for a consumer todislodge both bead l8 and bead 20. The closure portion of cap 1 may bereplaced by pushing downwardly on disk 2. The bead 18 then snaps intogroove 40 and the cap is again positioned. The closure may be performedas may times as desired.

Although the foregoing invention has been described in some detail, byway of illustration and example, for purposes of clarity andunderstanding, it is understood that certain changes and modificationsmay be practiced within the spirit of the invention and such are withinthe scope of the invention as defined by the appended claims.

I claim:

l. A deformable plastic cap comprising ill a top disk. (2) a cylindricalthin-walled outer skirt integrally attached to and extendingsubstantially perpendicularly from said disk and (3) a cylindrical innerskirt integrally attached to and substantially perpendicular to saiddisk positioned inward and enclosed within said outer skirt andsubstantially co-axial therewith and extending for a shorter distancethan said outer skirt; said outer skirt scored and weakened along acircumferential first score line downwardly spaced from said disk, andscore and weakened along a circumferential second score line spaceddownwardly from said first score line to form a weakened cylindricalband within said outer skirt, a tab attached to said cylindrical bandand extending from said band and outwardly from said outer skirt, aweakened area extending between said first score line and said secondscore line immediately adjacent said tab, a narrow radial first beadextending circumferentially around the inside and integrally attached tosaid outer skirt between said first score line and said disk, and anarrow radial second bead extending circumferentially around the insideand intergrally attached to said outer skirt below said second scoreline.

2. The deformable cap defined in claim 1 wherein said first bead andsaid second bead have a semi-circular cross-sectional area.

3. The deformable cap defined in claim 1 wherein said top disk has aflat circular lip extending outwardly beyond said outer skirt.

4. The deformable cap defined in claim 1 wherein said cap is made ofpolyethylene or polystyrene.

5. The deformable cap defined in claim 1 wherein said weakened area is ascore line connecting said first score line with said second score line.

6. The deformable cap defined in claim 1 wherein said first score lineand said second score line are made along the outside of said outerskirt.

7. In combination, (1 a container with a cylindrical neck having anopening through said neck to said con tainer, said neck having ancircumferential upper groove around the outside of said neck and acircumferential lower groove around said neck spaced downward from saidupper groove, and (2) a deformable plastic cap comprising a top disk, acylindrical thinwalled outer skirt integrally attached and substantiallyperpendicular to said disk and of a sufficient diameter so as to fitaround the exterior of said neck, a cylindrical inner skirt integrallyattached and substantially perpendicular to said disk inwardly spacedfrom said outer skirt and co-axial therewith so as to fit within saidopening; said outer skirt scored and weakened along a circumferentialfirst score line downwardly spaced from said disk, and scored andweakened along a circumferential second score line spaced downwardlyfrom said first score line to form a weakened cylindrical band withinsaid outer skirt, a tab attached to said cylindrical band and extendingdownwardly from said band and outwardly from said outer skirt. aweakened area extending between said first score line and said secondscore line immediately adjacent said tab, a narrow first bead extendingcircumferentially around the inside and integrally attached to saidouter skirt between said first score line and said disk and spaced so asto fit into said upper groove, and a narrow radial see ond beadextending circumferentially around the inside and integrally attached tosaid outer skirt below said second score line and spaced so as to fitinto said lower groove,

1. A deformable plastic cap comprising (1) a top disk, (2) a cylindricalthin-walled outer skirt integrally attached to and extendingsubstantially perpendicularly from said disk and (3) a cylindrical innerskirt integrally attached to and substantially perpendicular to saiddisk positioned inward and enclosed within said outer skirt andsubstantially co-axial therewith and extending for a shorter distancethan said outer skirt; said outer skirt scored and weakened along acircumferential first score line downwardly spaced from said disk, andscore and weakened along a circumferential second score line spaceddownwardly from said first score line to form a weakened cylindricalband within said outer skirt, a tab attached to said cylindrical bandand extending from said band and outwardly from said outer skirt, aweakened area extending between said first score line and said secondscore line immediately adjacent said tab, a narrow radial first beadextending circumferentially around the inside and integrally attached tosaid outer skirt between said first score line and said disk, and anarrow radial second bead extending circumferentially around the insideand intergrally attached to said outer skirt below said second scoreline.
 2. The deformable cap defined in claim 1 wherein said first beadand said second bead have a semi-circular cross-sectional area.
 3. Thedeformable cap defined in claim 1 wherein said top disk has a flatcircular lip extending outwardly beyond said outer skirt.
 4. Thedeformable cAp defined in claim 1 wherein said cap is made ofpolyethylene or polystyrene.
 5. The deformable cap defined in claim 1wherein said weakened area is a score line connecting said first scoreline with said second score line.
 6. The deformable cap defined in claim1 wherein said first score line and said second score line are madealong the outside of said outer skirt.
 7. In combination, (1) acontainer with a cylindrical neck having an opening through said neck tosaid container, said neck having an circumferential upper groove aroundthe outside of said neck and a circumferential lower groove around saidneck spaced downward from said upper groove, and (2) a deformableplastic cap comprising a top disk, a cylindrical thin-walled outer skirtintegrally attached and substantially perpendicular to said disk and ofa sufficient diameter so as to fit around the exterior of said neck, acylindrical inner skirt integrally attached and substantiallyperpendicular to said disk inwardly spaced from said outer skirt andco-axial therewith so as to fit within said opening; said outer skirtscored and weakened along a circumferential first score line downwardlyspaced from said disk, and scored and weakened along a circumferentialsecond score line spaced downwardly from said first score line to form aweakened cylindrical band within said outer skirt, a tab attached tosaid cylindrical band and extending downwardly from said band andoutwardly from said outer skirt, a weakened area extending between saidfirst score line and said second score line immediately adjacent saidtab, a narrow first bead extending circumferentially around the insideand integrally attached to said outer skirt between said first scoreline and said disk and spaced so as to fit into said upper groove, and anarrow radial second bead extending circumferentially around the insideand integrally attached to said outer skirt below said second score lineand spaced so as to fit into said lower groove.